Method of determining volatile organic compounds

ABSTRACT

A number of variations may involve a method that may include providing a non-conductive layer. A conductive layer may be provided and may overly the non-conductive layer to form a sensor device. The presence of a volatile organic compound may be determined by monitoring the conductive layer.

CROSS REFERENCE TO RELATED APPLICATION

This application is a U.S. National-Stage entry under 35 U.S.C. § 371based on International Application No. PCT/US16/30029, filed Apr. 29,2016, which was published under PCT Article 21(2) and claims benefit ofU.S. Provisional Application No. 62/186,568 filed Jun. 30, 2015.

TECHNICAL FIELD

The field to which the disclosure generally relates includes sensordevices and methods of making them and using them to measure variables.

BACKGROUND

In a number of variations, sensor devices may be used to measureenvironmental conditions, or variables pertaining to components.

SUMMARY OF ILLUSTRATIVE VARIATIONS

A number of variations may involve a method that may include providing anon-conductive layer. A conductive layer may be provided and may overlythe non-conductive layer to form a sensor device. The presence of avolatile organic compound may be determined by monitoring the conductivelayer.

A number of other variations may involve a method and may includeproviding a non-conductive layer. The non-conductive layer may bepositioned to monitor a potential source for a volatile organiccompound. A conductive layer may be provided overlying at least a partof the non-conductive layer with the conductive layer to form a sensordevice. A presence of a volatile organic compound in the non-conductivelayer may be determined by monitoring the conductive layer.

A number of additional variations may involve a method that may includeproviding a substrate. A sensor device may be provided coupled to thesubstrate and may include a non-conductive layer and a conductive layeroverlying the non-conductive layer constructed and arranged to measureor monitor at least one variable of a volatile organic compound. Atleast one of deformation of the non-conductive layer or substrate, or achange in an opposition to current in the conductive layer may bedetermined to provide measurement or monitoring of the at least onevariable based on at least one calculation.

Other illustrative variations within the scope of the invention willbecome apparent from the detailed description provided hereinafter. Itshould be understood that the detailed description and specificexamples, while disclosing variations within the scope of the invention,are intended for purposes of illustration only and are not intended tolimit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Select examples of variations within the scope of the invention willbecome more fully understood from the detailed description and theaccompanying drawings, wherein:

FIG. 1 illustrates a product according to a number of variations.

FIG. 2 illustrates a product according to a number of variations.

FIG. 3 illustrates a graph of volatile organic compounds in relation tomeasured resistance of a product versus concentration, according to anumber of variations.

FIG. 4 illustrates a graph of response to volatile organic compounds inrelation to measured resistance versus time of a product according to anumber of variations.

FIG. 5 illustrates methods according to a number of variations.

FIG. 6 illustrates methods according to a number of variations.

DETAILED DESCRIPTION OF ILLUSTRATIVE VARIATIONS

The following description of the variations is merely illustrative innature and is in no way intended to limit the scope of the invention,its application, or uses.

FIGS. 1 and 2 show a product 10 according to a number of variations. Ina number of variations, the product 10 may include a substrate 12. In anumber of variations, the product 10 may include a sensor device 14. Thesensor device 14 may include a non-conductive layer 16. The sensordevice 14 may include a conductive layer 18. The conductive layer 18 mayoverlie the non-conductive layer 16. In a number of variations, thesensor device 14 may overlie, or may otherwise be in physical contactwith, the substrate 12. In a number of variations, the sensor device 14may be in close proximity to the substrate 12 or at any location wheresensing is desired. In a number of variations, the sensor device 14 maybe constructed and arranged to measure or monitor at least one variable.The variable may involve a physical property such as temperature,pressure (strain), deformation, or another property, or may involvedetection, identification, classification, tracking, or othercharacteristics of a property. The variable may involve concentration,quantity, rate, time or another characteristic of a compound, such asvolatile organic compound concentration. The variable may involve astatus of a device or environment such as state of charge, or state ofhealth of the substrate 12, depletion status, diagnosis properties, orother variables indicative of status. In a number of variations, thesubstrate 12 may include a two dimensional surface. In a number ofvariations, the substrate 12 may include a three dimensional surface. Ina number of variations, the sensor device 14 may be used to cover thesubstrate 12 surface area at a percentage from 0 to 100%. In a number ofvariations, a plurality of sensor devices 14 may be used to cover thesubstrate 12 surface area at a percentage from 0 to 100%. In a number ofvariations, the substrate 12 may include a battery or battery exteriorsurface. In a number of variations the substrate 12 may include any hostfor which monitoring with the sensor device 14 is desirable. In a numberof variations, the operation of the battery may be controlled via abattery control module (BCM) 23. In a number of variations, thesubstrate 12 may include a lithium ion battery 13 including, but notlimited to, the battery pouch, housing, or casing. In a number ofvariations, the substrate 12 may include a cooling fin, cooling finexterior, or surface of the battery 13. In a number of variations, thesubstrate 12 may include a battery or cooling fin for a vehicleincluding but not limited to, a motor vehicle, watercraft, spacecraft,aircraft, or may be another type. In a number of variations, the sensordevice 14 may include at least one lead 22. In a number of variationsthe sensor device 14 may comprise the non-conductive layer 16, theconductive layer 18 and the lead 22. Resistance and impedance may begenerally referred to an opposition to the passage of an applied currentfrom a DC or AC source, through an area of interest as detected throughthe one or more leads 22. In a number of variations, the sensor device14 may include a data acquisition module (DAQ) 24. In a number ofvariations, the sensor device 14 may be electrically isolated from thesubstrate 12. In a number of variations, the sensor device 14 or dataacquisition module 24 may be electrically coupled to an electroniccontrol module (ECM) 25, which may be a controller for processinginformation, and may be included in a mobile or stationary host. As usedherein, the term “electrically coupled” may mean possessing the abilityto transfer electrons or electric signals between the at least twocomponents. As used herein, the term “electrically coupled” relationshipmay include a conducting wire or may include wireless connection. In anumber of variations, the at least one variable may be measured viainputs of at least one of deformation of the non-conductive layer 16 orsubstrate 12, or change in opposition to current of the conductive layer18 through one or more areas of interest, which may involve at least onecalculation such as determining the change, rate of change, orcomparison with a threshold. In a number of variations, the sensordevice 14 may be physically attached to the substrate 12 through anattachment 50. In a number of variations, the substrate 12 could be anelectrical component. In a number of variations, the substrate 12 couldbe a foodstuff packaging component. In a number of variations, thesubstrate 12 could be a fiber optic component.

In a number of variations, the non-conductive layer 16 may include apolymeric material. The non-conductive layer 16 may comprise a polymerincluding, but not limited to, Acrylonitrile butadiene styrene (ABS),Polymethyl Methacrylate (PMMA), Celluloid, Cellulose acetate,Cycloolefin Copolymer (COC), Ethylene-Vinyl Acetate (EVA), Ethylenevinyl alcohol (EVOH), Fluoroplastics (including PTFE, FEP, PFA, CTFE,ECTFE, ETFE) Ionomers, Kydex™, a trademarked acrylic/PVC alloy, LiquidCrystal Polymer (LCP), Polyacetal (POM or Acetal), Polyacrylates(Acrylic), Polyacrylonitrile (PAN or Acrylonitrile), Polyamide (PA orNylon), Polyamide-imide (PAI), Polyaryletherketone (PAEK or Ketone),Polybutadiene (PBD), Polybutylene (PB), Polybutylene terephthalate(PBT), Polycaprolactone (PCL), Polychlorotrifluoroethylene (PCTFE),Polyethylene terephthalate (PET), Polycyclohexylene dimethyleneterephthalate (PCT), Polycarbonate (PC), Polyhydroxyalkanoates (PHAs),Polyketone (PK), Polyester, Polyetheretherketone (PEEK),Polyetherketoneketone (PEKK), Polyetherimide (PEI), Polyethersulfone(PES), Polysulfone, Polyethylenechlorinates (PEC), Polyimide (PI),Polylactic acid (PLA), Polymethylpentene (PMP), Polyphenylene oxide(PPO), Polyphenylene sulfide (PPS), Polyphthalamide (PPA), Polystyrene(PS), Polysulfone (PSU), Polytrimethylene terephthalate (PTT),Polyurethane (PU), Polyvinyl acetate (PVA), Polyvinyl chloride (PVC),Polyvinylidene chloride (PVDC), Styrene-acrylonitrile (SAN),polycarbonate+acrylonitrile butadiene styrene mix (ABS+PC),Polypropylene (PP) (including, but not limited to, impact, random, andhomo), Polyethylene (PE) (including, but not limited to, linear lowdensity, linear high density), combinations or blends in any amountthereof, or may be another type. In a number of variations, thenon-conductive layer 16 may be a combination of the above polymers inany amount or concentration. In a number of variations, thenon-conductive layer 16 may include a composite layer comprising severallayers of the materials listed. In a number of variations, thenon-conductive layer 16 may be formed via a method including, but notlimited to, injection molding, extrusion molding, structural foam,vacuum forming, extrusion blow molding, a hand lay-up operation, a spraylay-up operation, a pultrusion operation, a chopped strand mat, vacuumbag molding, pressure bag molding, autoclave molding, resin transfermolding, vacuum assisted resin transfer molding, bladder molding,compression molding, mandrel wrapping, wet layup, chopper gun, filamentwinding, melting, staple fiber, continuous filament, lamination, or maybe formed another way.

In a number of variations, the conductive layer 18 may include ametallic or semi-metallic material. In a number of variations, theconductive layer 18 may include a metal including, but not limited to,plastic steel, stainless steel, copper, nickel, tin, gold, silver,molybdenum, palladium, tungsten, graphite, zinc, iron, bronze, aluminum,titanium, platinum, silicide, or may be another type), metallic alloys,graphite, graphene, another form of carbon, combinations thereof, or maybe another type. In a number of variations the conductive layer mayinclude a non-metal material that conducts electric current sufficientto measure changes in impedance or resistance. In a number ofvariations, the conductive layer 18 may be a combination of thematerials in any amount or concentration. In a number of variations, theconductive layer 18 may include a composite layer comprising severallayers of the materials. In a number of variations, the conductive layer18 may be formed on or overlying the non-conductive layer 16 via amethod including, but not limited to, inkjet/laser printing, 3-Dprinting, casting, extrusion, forging, plating (electroless, electro),plasma spraying, aerosol spraying, thermal spraying, dip coating,roll-to-roll coating, spin coating, spray coating, chemical solutiondeposition, thermal evaporation, pulsed laser deposition, cathodic arcdeposition, or known etching techniques (i.e. sputter, Chemical VaporDeposition, Physical Vapor Disposition, Atomic Vapor Disposition, ALD,or combination of deposition and thermal growth), conversion coating,ion beam mixing, thin film printing, or may be formed another way.

In a number of variations, the at least one lead 22 may include aconductor such as a metal material, and may be used to measureresistance or impedance in an area of interest. In a number ofvariations, the at least one lead 22 may include a metal including, butnot limited to, plastic steel, stainless steel, copper, nickel, tin,gold, silver, molybdenum, palladium, tungsten, graphite, zinc, iron,bronze, aluminum, titanium, platinum, silicide, or may be another type),metallic alloys, combinations thereof, or may be another type ofelectrical conducting material. In a number of variations, the at leastone lead 22 may be a combination of materials in any amount orconcentration. In a number of variations, the at least one lead 22 mayinclude a composite layer comprising several layers of materials. In anumber of variations, the at least one lead 22 may be formed on oroverlying the conductive layer 18, or otherwise in contact therewith(such as being formed on the non-conductive layer 16), via a methodincluding, but not limited to, inkjet/laser printing, 3-D printing,casting, extrusion, forging, plating (electroless, electro), plasmaspraying, thermal spraying, dip coating, roll-to-roll coating, spincoating, spray coating, chemical solution deposition, thermalevaporation, pulsed laser deposition, cathodic arc deposition, or knownetching techniques (i.e. sputter, Chemical Vapor Deposition, PhysicalVapor Disposition, Atomic Vapor Disposition, ALD, or combination ofdeposition and thermal growth), conversion coating, ion beam mixing,thin film printing, or may be formed another way. In a number ofvariations, the at least one lead 22 may be attached to the conductivelayer 18, or the non-conductive layer 16, through an adhesive comprisingat least one of, silver paste, acrylonitrile, cyanoacrylate, acrylic,resorcinol glue, epoxy resin, epoxy putty, ethylene-vinyl acetate,phenol formaldehyde resin, polyamide, polyester, polyethylene,polypropylene, polysulfides, polyurethane, polyvinyl acetate, polyvinylalcohol, polyvinyl chloride, polyvinyl chloride emulsion,polyvinylpyrrolidone, rubber cement, silicone, combinations thereof, ormay be another type. The contact between the impedance leads and theconductive surface may be ohmic or nearly ohmic. A conductive adhesivemay be used or a metal with direct contact to the conducting layer maybe applied by printing, CVD, PVD, or another process. In a number ofvariations as shown in FIG. 1, the leads may be provided individually,or in pairs with different spacing. For example a first pair may have aspacing that represents a distance 21 between the leads 22 and a secondpair may have a second spacing of a distance 23 that may have a greaterdistance between the leads 22. The distances 21, 23 may span areas ofinterest for monitoring changes in opposition to current. In a number ofvariations providing different distances between the pairs of leadsenables tailoring the sensitivity of the sensor device 14. In a numberof variations providing different distances 21, 23 may provideindications of different threshold concentrations of an analyte. Forexample, a first concentration may report through the distance 21 andnot through the distance 23, and a second greater concentration mayreport through the distance 21 and the distance 23. A similar result maybe achieved by varying the contact resistance between individual leads22 and the conductive layer 18.

In a number of variations, the sensor device 14 may be physicallyattached to the substrate 12 via an attachment 50. In a number ofvariations, the attachment 50 may include an adhesive including at leastone of, acrylonitrile, cyanoacrylate, acrylic, resorcinol glue, epoxyresin, epoxy putty, ethylene-vinyl acetate, phenol formaldehyde resin,polyamide, polyester, polyethylene, polypropylene, polysulfides,polyurethane, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride,polyvinyl chloride emulsion, polyvinylpyrrolidone, rubber cement,UV-cure, silicone, combinations thereof, or may be another type.

In a number of variations, the sensor device 14, non-conductive layer16, and/or conductive layer 18 may operate as or include a strain gauge.In a number of variations, the sensor device 14, non-conductive layer16, and/or conductive layer 18 may be used to operate as a strain gaugeto measure state of charge (SOC) or state of health (SOH) of a battery,or other status, by measuring deformation of the substrate 12 and/ornon-conductive layer 16, or change in resistance of the conductive layer18 through at least one calculation. In a number of variations, SOC orSOH calculation may include several percent changes in resistance overthe charge window and larger variations for lower state of health.Thermal expansion of the non-conductive layer 16 and conductive layer 18may be compensated through variations in sensor layout. Multiple leads22 may be used to pinpoint a location of deformation, wherein differentchanges may be detected through different leads at positioned at knownlocations In a number of variations, the sensor device 14,non-conductive layer 16, and/or conductive layer 18 may be used tooperate as a strain gauge to measure compounds such as volatile organiccompounds (VOC's) in vapor state by measuring deformation of thesubstrate 12 and/or non-conductive layer 16, or change in resistance ofthe conductive layer 18 through at least one calculation. In a number ofvariations, the VOC's may include, but are not limited to, aromatichydrocarbons, octane, ketones, or aldehydes, glycols, or may be anothercompound. In a number of variations, resistance changes comparable toSOC changes, though with a significantly different temporal response,may be registered for VOC sensing. In a number of variations, thepresence of VOC's may indicate electrolyte decomposition within thesubstrate 12 or battery or leaks within the substrate 12 as a pouch,casing or housing. In a number of variations, electrolyte decompositionmay decrease the life cycle of the battery. FIG. 3 illustrates arelation of the VOC concentration to resistance measured in theconductive layer according to a number of variations. The resistancechange in ohms of the sensor device 14 is shown on the vertical axis asa function of analyte vapor concentrations presented in parts permillion on the horizontal axis. Proportional responses are demonstratedfor acetone at curve 26, methanol at curve 27 and xylene at curve 28. Ina number of variations, the non-conductive coating 16 and/or conductivecoating of the sensor device 14 may be used to operate as a PTCthermocouple to measure temperature of the substrate 12 or the area inclose proximity to the substrate 12 through at least one calculation. Ina number of variations, the pressure calculation may include severalpercent change in the resistance of the conductive coating. In a numberof variations, the non-conductive coating 16 and/or conductive coatingof the sensor device 14 may be used to operate as a PTC thermocouple tomeasure temperature of the substrate 12 or the area in close proximityto the substrate 12 through at least one calculation. In a number ofvariations, the pressure calculation may include a lower response forPTC by several fractions of a percent. In a number of variations, wherethe substrate 12 is a cooling fin, the non-conductive coating 16 and/orconductive coating of the sensor device 14 may be used to operate as aflowmeter to measure flowrate of the coolant surrounding the substrate12 or the area in close proximity to the substrate 12 by measuringdeformation of the substrate 12 and/or non-conductive layer 16, orchange in resistance of the conductive layer 18 through at least onecalculation. In a number of variations, the flowrate calculation mayinclude several percent to tens of percent change in the resistance ofthe conductive coating. In a number of variations, the sensor device 14may cover the entirety of the substrate 12 and act as a grid-like systemof interconnected sensor devices 14 to provide inputs to determinevariables at a number of locations on or in close proximity to thesubstrate 12 to provide local and overall variable (including, but notlimited to, temperature, pressure (strain), volatile organic compoundconcentration, state of charge, or state of health of the substrate 12)measurement and monitoring through at least one calculation. In a numberof variations the sensor device 14 provides the ability to detect VOCsin low concentrations through deformation induced by VOC absorption inan electrically insulating polymer-non-conducting layer 16. Thedeformation may be detected by measuring changes in resistance orimpedance of the conductive coating and/or of the non-conducting layer16. Direct current may be used, and alternating current is andalternative. The polymer non-conducting layer 16 may absorb the organicgas phase compounds causing micro swelling and elastic deformation. Theresulting strain may modify the conduction paths of the conductive layer18 resulting in a measurable resistance or impedance change. The abilityto discriminate to analytes of choice, in the sensor device 14 with arapid response, reversibility and high sensitivity is provided.

In a number of variations, placement of a plurality of sensor devices 14onto various locations on or in close proximity to a substrate 12 maydecouple the deformation measurements of the substrate 12 and/ornon-conductive layer 16 to provide more accurate measurement andmonitoring on deformation related to SOC or SOH versus deformationrelated to the presence of VOC's. Comparable resistance changes may beindicated by all three but all may have a different temporal response.SOC changes may be cyclical in nature, SOH changes may be persistent,and VOC induced changes may be rapid and may be sustained. In a numberof variations, this may allow the sensor device 14 or plurality ofsensor devices 14 to measure the presence of VOC's in relation to thesubstrate 12 independent of the state of charge or state of healthmeasurements of the substrate 12 via a calculation and may be measuredindependent of SOC or SOH measurement through the use of the PTCthermocouple.

In a number of variations, spikes in the measured resistance, asillustrated as spike 29 in FIG. 4 for example, may indicate a change orincrease in presence of VOC's while rate of change in the resistance mayindicate a change in the state of charge or state of health of the cell.SOH changes may be persistent and may result in sustained higherresistance or lower than expected resistances over the SOC window. In anumber of variations, placement of a plurality of sensor devices 14 ontovarious locations on or in close proximity to a substrate 12 maydecouple the deformation measurements of the substrate 12 and/ornon-conductive layer 16 to provide more accurate measurement andmonitoring on deformation related to SOC or SOH versus deformationrelated to the temperature or pressure. Modulation of sensor probespacing may allow for a linear regression response for CTE whiledeformation due to SOC and SOH changes may represent significantdepartures from the nonlinear behavior over the plurality of probespacing. In a number of variations, temperature or pressure may beindicated through deformation measurements of the substrate 12 and/orsource generating the VOC. For example, the sensor device 14 may beexposed to acetone introduced to the sensing device 14 in the presenceof air flow. A measured resistance of greater than the baseline ofapproximately 10 ohms may indicate the presence of acetone in theenvironment, while the rapid change from the baseline to the peak 29 mayindicate an underlying change in the operation being monitored, wherethe changes results in the generation or release of additional acetonefrom a norm. As demonstrated, the sensor device 14 responds to theintroduction of analytes quickly and returns to the baseline resistanceafter the exposure demonstrating a rapid and reversible response. As canbe seen the signal to noise of the response is very good and theresponse nearly instantaneous. Return to the base line within secondsdemonstrates that very small and quick changes in environmental qualitycan be detected readily.

With reference again to FIG. 1, in a number of variations, the DAQ 24 orthe ECM 25 may receive and process input from at least one sensor device14 in light of stored instructions and/or data, determine a variablethrough at least one calculation, and transmit output signals to variousreceptors or actuators, including, but not limited to, the substrate 12,the battery, the cooling fin, the battery control module (BCM) 23 orvehicle itself may include, for example, an electrical circuit, anelectronic circuit or chip, and/or a computer. In an illustrativecomputer variation, the data acquisition module (DAQ) 24, batterycontrol module (BCM) 23, or electronic control module (ECM) 25 generallymay include one or more processors, or memory storage units that may becoupled to the processor(s), and one or more interfaces electricallycoupling the processor(s) to one or more other devices, including atleast one of the other of the data acquisition module (DAQ) 24, batterycontrol module (BCM) 23, or electronic control module (ECM) 25, or tothe at least one sensor device 14, or to a different component of avehicle. The processor(s) and other powered system devices (including atleast one of the other of the data acquisition module (DAQ) 24, batterycontrol module (BCM) 23, electronic control module (ECM) 25, or to theat least one sensor device 14) may be supplied with electricity by apower supply, for example, a generated and distributed power source, thebattery 13 itself, other fuel cells, a vehicle engine, other vehiclepower component, or other source. The processor(s) may executeinstructions or calculations that provide at least some of thefunctionality for the sensor device 14 and methods 800, 900. As usedherein, the term instructions may include, for example, control logic,computer software and/or firmware, programmable instructions, or othersuitable instructions. The processor may include, for example, one ormore microprocessors, microcontrollers, application specific integratedcircuits, programmable logic devices, field programmable gate arrays,and/or any other suitable type of electronic processing device(s).

Also, in a number of variations, the data acquisition module (DAQ) 24,battery control module (BCM) 23, or electronic control module (ECM) 25,may be configured to provide storage for data received by or loaded tothe at least one of the other of the data acquisition module (DAQ) 24,battery control module (BCM) 23, or electronic control module (ECM) 25,or to the at least one sensor device 14, or to a different component ofa vehicle, or the like, for processor-executable instructions orcalculations. The data, calculations, and/or instructions may be stored,for example, as look-up tables, formulas, algorithms, maps, models,and/or any other suitable format. The memory may include, for example,RAM, ROM, EPROM, and/or any other suitable type of storage articleand/or device.

In a number of variations, the interfaces may include, for example,analog/digital or digital/analog converters, signal conditioners,amplifiers, filters, other electronic devices or software modules,and/or any other suitable interfaces. The interfaces may conform to, forexample, RS-232, parallel, small computer system interface, universalserial bus, CAN, MOST, LIN, FlexRay, and/or any other suitableprotocol(s). The interfaces may include circuits, software, firmware, orany other device to assist or enable the data acquisition module (DAQ)24, battery control module (BCM) 23, or electronic control module (ECM)25, in communicating with other devices.

In a number of variations, the methods or parts thereof may beimplemented in a computer program product including instructions orcalculations carried on a computer readable medium for use by one ormore processors to implement one or more of the method steps orinstructions. The computer program product may include one or moresoftware programs comprised of program instructions in source code,object code, executable code or other formats; one or more firmwareprograms; or hardware description language (HDL) files; and any programrelated data. The data may include data structures, look-up tables, ordata in any other suitable format. The program instructions may includeprogram modules, routines, programs, objects, components, and/or thelike. The computer program may be executed on one processor or onmultiple processors in communication with one another.

In a number of variations, the program(s) can be embodied on computerreadable media, which can include one or more storage devices, articlesof manufacture, or the like. Illustrative computer readable mediainclude computer system memory, e.g. RAM (random access memory), ROM(read only memory); semiconductor memory, e.g. EPROM (erasable,programmable ROM), EEPROM (electrically erasable, programmable ROM),flash memory; magnetic or optical disks or tapes; and/or the like. Thecomputer readable medium also may include computer to computerconnections, for example, when data may be transferred or provided overa network or another communications connection (either wired, wireless,or a combination thereof). Any combination(s) of the above examples isalso included within the scope of the computer-readable media. It istherefore to be understood that the method may be at least partiallyperformed by any electronic articles and/or devices capable of executinginstructions corresponding to one or more steps of the disclosedmethods.

In a number of variations, as shown in FIG. 5, a method 800 is shown. Ina number of variations, the method 800 may include a step 802 ofproviding a substrate 12. The method 800 further includes step 804 ofproviding a non-conductive layer 16 and overlying the substrate 12 withthe non-conductive layer 16, or mounting the non-conductive layer 16 onthe substrate 12. The method 800 may further include step 806 ofproviding a conductive layer 18 and overlying the non-conductive layer16 with the conductive layer 18 to form a sensor device 14 constructedand arranged to measure or monitor at least one variable comprising atleast one of temperature, pressure (strain), volatile organic compoundconcentration, state of charge, or state of health of the substrate 12,or the environment around the non-conductive layer 16. In a number ofvariations, as shown in FIG. 6, a method 900 is shown. The method 900may include a step 902 of providing a substrate 12. The method 900 mayfurther include step 904 of providing a sensor device 14 electronicallycoupled to the substrate 12 comprising a non-conductive layer 16 and aconductive layer 18 overlying the non-conductive layer 16 constructedand arranged to measure or monitor at least one variable comprising atleast one of temperature, pressure (strain), volatile organic compoundconcentration, state of charge, or state of health of a substrate 12.The method 900 further includes step 906 of determining at least one ofdeformation of the non-conductive layer 16 or the substrate 12, orchange in resistance of the conductive layer 18 to provide measurementor monitoring of the at least one variable based on at least onecalculation. In a number of variations the lead(s) 22 may be connectedto a power source, such as the battery 13. In a number of variations thelead(s) 22 may be provided in any manner to be electrically coupled tomeasure resistance or impedance in the conductive layer 18. In a numberof variations the lead(s) 22 may be provided in differently spacedpairs. The methods 800, 900 may include providing a mechanism to monitorthe response of the non-conductive layer 16, which may include providingthe DAQ 24. In a number of variations the DAQ 24 may be connected withthe lead(s) 22 to collect information. In a number of variations thelead(s) 22 may be connected directly to the ECM 25 to collectinformation. In a number of variations the DAQ 24 may monitor forresistance or impedance changes between a pair of leads 22. The methods800, 900 may further include a step of determining a deformation of thenon-conductive layer 16 by monitoring for a change in resistance betweenthe lead(s) 22 to provide measurement or monitoring of a VOC in theenvironment surrounding the sensing device 14. In a number of variationsthe methods 800, 900 may include determining the type of VOC sensed,such as by comparing the magnitude and/or the rate of the resistancechange to known resistance changes for different types of VOCs, such asthrough a lookup table reference. In a number of variations the methods800, 900 may include determining the concentration of VOC sensed, suchas by comparing the magnitude of the resistance change to knownresistance changes for different types of VOCs, such as through a lookuptable reference. In a number of variations the methods 800, 900 mayinclude monitoring for a change in an operation or an environment, wherethe changes results in the generation or release of additional VOC. Forexample, the normal presence of a varying amount of analyte may beaccompanied by a rate of change indicative of an abnormal event. In anumber of variations the methods 800, 900 may include determining therise time between a baseline and a peak 29, and may include determiningthe magnitude of the peak 29 to determine the type of VOC sensed basedits molecular weight. In a number of variations, the methods 800, 900may use the non-conductive layer 16 and/or conductive layer 18 of thesensor device 14 to operate as a PTC thermocouple to measuringtemperature of a substrate to which the sensor device 14 may be mountedor the area in close proximity to the sensor device 14 through at leastone calculation. In a number of variations, the methods 800, 900 mayinclude applying the sensor device 14 to cover relevant parts of thesubstrate 12 to which it may be mounted and may act as a grid-likesystem of interconnected sensor devices 14 to provide inputs todetermine variables at a number of locations to provide local andoverall variable (including, but not limited to, temperature, pressure,deformation, or volatile organic compound concentration), measurementand monitoring through at least one calculation. In a number ofvariations the sensor device may monitor for degradation of a substrate,such as a battery or welding electrodes by monitoring for the presenceof VOCs. Degradation can be described as any generation or release of aVOC at which monitoring is targeted.

As detailed above, the sensor device 14 may have multiple advantagesincluding superior long term stability of the sensor since the polymer'schemical reactivity to the ambient environment is decoupled from thetransduction mechanism through inclusion of the conductive layer 18, afaster response, and a higher degree reversibility since the transducedsignal does not rely on a chemical interaction between the polymer andanalyte. Use of the non-conducting layer 16 supports performance withouta need to be shielded the sensor device 14 from water and oxygen sincethe polymer will not degrade over time. The sensor device 14 may be usedfor analyte detection, identification, classification, and/or trackingthrough a polymer non-conducting layer 16 with conductive layer 18 thatmay be provided as a coating on the non-conducting layer 16. Electricalresistance or impedance changes may be used for analyte classification.Signal processing for the detection, identification, classificationand/or tracking of a narrow band of likely analyte. Tuning sensitivityfor a specific analyte may be accomplished by altering the compositionof the non-conductive layer 16. For example, PMMA may be used due to itssensitivity to polar compounds while PE or PP may be used due to theirsensitivity to nonpolar species. An array of sensors with uniqueresponse to individual analyte may be used for classifications. Examplesof uses of the products and methods described herein may include foodquality inspection, pharmaceutical processing, chemical synthesis,beverage processing, monitoring for health purposes, cosmeticproduction, manufacturing plant monitoring, vehicle interior airquality, residential air evaluation, vehicle shed testing, or anyapplication where the monitoring, detection, identification,classification, and/or tracking of analytes is desired.

The following description of variants is only illustrative ofcomponents, elements, acts, product and methods considered to be withinthe scope of the invention and are not in any way intended to limit suchscope by what is specifically disclosed or not expressly set forth. Thecomponents, elements, acts, product and methods as described herein maybe combined and rearranged other than as expressly described herein andstill are considered to be within the scope of the invention.

Variation 1 may involve a method that may include providing anon-conductive layer. A conductive layer may be provided and may overlythe non-conductive layer to form a sensor device. The presence of avolatile organic compound may be determined by monitoring the conductivelayer.

Variation 2 may include the method of variation 1 and may includeproviding a number of leads that may be electrically coupled with theconductive layer.

Variation 3 may include the method of variation 2 and may includepassing electrical current through the leads and into the conductivelayer. Monitoring may be conducted for changes in an opposition to thecurrent through the conductive layer.

Variation 4 may include the method of variation 1 and may includeproviding a substrate. The non-conductive layer may be positionedrelative to the substrate. Monitoring of the substrate with the sensordevice may be conducted. The status of the substrate may be determinedthrough changes in the conductive layer.

Variation 5 may include the method of variation 4 wherein determiningthe status of the substrate comprises determining a degradation of thesubstrate by detecting the presence of the volatile organic compound.

Variation 6 may include the method of variation 5 and may includepositioning the sensor in contact with the substrate.

Variation 7 may include the method of variation 1 and may includeproviding a number of leads each of which may be electrically coupledwith the conductive layer. The leads may be placed in variation to theother, such as with different distances or electrical conduction. Aconcentration of the volatile organic compound may be determined bymeasuring an opposition to current through the conductive layer from atleast some of the number of leads.

Variation 8 may include the method of variation 1 and may includemeasuring an opposition to current in the conductive layer. A comparisonmay be made of at least one of a magnitude of the opposition, or a rateof change of the opposition, to known values.

Variation 9 may include the method of variation 1 and may includeexposing the non-conductive layer to the volatile organic compound. Thevolatile organic compound may be allowed to expand by the exposure. Theexpansion may be detected through a change in an opposition to currentin the conducting layer.

Variation 10 may involve a method and may include providing anon-conductive layer. The non-conductive layer may be positioned tomonitor a potential source for a volatile organic compound. A conductivelayer may be provided overlying at least a part of the non-conductivelayer with the conductive layer to form a sensor device. A presence of avolatile organic compound in the non-conductive layer may be determinedby monitoring the conductive layer.

Variation 11 may include the method of variation 10 and may includeidentifying a category of the volatile organic compound to monitor. Apolymer may be selected that responds to exposure to the category byexpanding differently than to other compounds. The non-conductive layermay be formed of the polymer.

Variation 12 may include the method of variation 10 and may includeproviding a number of leads electrically coupled with the conductivelayer. Electrical current may be passed through the leads and into theconductive layer. Changes in an opposition to the current passingthrough the conductive layer may be monitored.

Variation 13 may include the method of variation 12 and may includedetermining a concentration of the volatile organic compound. Avariation may be provided between individuals of the leads and theconductive layer. The opposition to current through the conductive layermay be measured from each of the number of leads, and the measurementsmay be compared to each other.

Variation 14 may include the method of variation 10 and may includeproviding a substrate. The non-conductive layer may be positionedrelative to a substrate. The substrate may be monitored with the sensordevice. A status of the substrate may be determined through changes inthe conductive layer.

Variation 15 may include the method of variation 14 wherein determiningthe status of the substrate may include determining a degradation of thesubstrate by detecting the presence of the volatile organic compound.

Variation 16 may include the method of variation 10 and may includemeasuring an opposition to current in the conductive layer. A comparisonmay be made of at least one of a magnitude of the opposition, or a rateof change of the opposition, to known values, such as produced byexposing the conductive layer to known VOCs and recording the resultingchanges. A type of the volatile organic compound may be determined fromthe comparison.

Variation 17 may include the method of variation 10 and may includeexposing the non-conductive layer to the volatile organic compound. Thenon-conductive layer may be allowed to expand from the exposure. Theexpansion may be detected through a change in an opposition to currentin the conducting layer.

Variation 18 may include the method of variation 10 and may includeproviding the non-conductive layer of polymethyl methacrylate to monitorfor a polar compound class as the volatile organic compound.

Variation 19 may include the method of variation 10 and may includeproviding the non-conductive layer of at least one of polypropylene orpolyethylene to monitor for a nonpolar compound class as the volatileorganic compound.

Variation 20 may involve a method that may include providing asubstrate. A sensor device may be provided coupled to the substrate andmay include a non-conductive layer and a conductive layer overlying thenon-conductive layer constructed and arranged to measure or monitor atleast one variable of a volatile organic compound. At least one ofdeformation of the non-conductive layer or substrate, or a change in anopposition to current in the conductive layer may be determined toprovide measurement or monitoring of the at least one variable based onat least one calculation.

The above description of select variations within the scope of theinvention is merely illustrative in nature and, thus, variations orvariants thereof are not to be regarded as a departure from the spiritand scope of the invention.

What is claimed is:
 1. A method comprising: providing a non-conductivelayer; providing a conductive layer and overlying the non-conductivelayer with the conductive layer to form a sensor device; and determiningthe presence of a volatile organic compound by monitoring the conductivelayer.
 2. The method of claim 1 comprising providing a number of leadselectrically coupled with the conductive layer.
 3. The method of claim 2comprising passing electrical current through the leads and into theconductive layer; and monitoring for changes in an opposition to thecurrent through the conductive layer.
 4. The method of claim 1comprising providing a substrate; positioning the non-conductive layerrelative to the substrate; monitoring the substrate with the sensordevice; and determining a status of the substrate through changes in theconductive layer.
 5. The method of claim 4 comprising whereindetermining the status of the substrate comprises determining at leastone of a degradation of the substrate by detecting the presence of thevolatile organic compound.
 6. The method of claim 5 comprisingpositioning the sensor in contact with the substrate.
 7. The method ofclaim 1 comprising providing a number of leads each electrically coupledwith the conductive layer in variation to the other; and determining aconcentration of the volatile organic compound by measuring anopposition to current through the conductive layer from at least some ofthe number of leads.
 8. The method of claim 1 comprising measuring anopposition to current in the conductive layer; and comparing at leastone of a magnitude of the opposition or a rate of change of theopposition to known values.
 9. The method of claim 1 comprising exposingthe non-conductive layer to the volatile organic compound; allowing thevolatile organic compound to expand by the exposure; and detecting theexpansion through a change in an opposition to current in the conductinglayer.
 10. A method comprising providing a non-conductive layer;positioning the non-conductive layer to monitor a potential source for avolatile organic compound; providing a conductive layer overlying atleast a part of the non-conductive layer with the conductive layer toform a sensor device; and determining a presence of a volatile organiccompound in the non-conducting layer by monitoring the conductive layer.11. The method of claim 10 comprising identifying a category of thevolatile organic compound to monitor; determining a polymer thatresponds to exposure to the category by expanding differently than toother compounds; and forming the non-conductive layer of the polymer.12. The method of claim 10 comprising providing a number of leadselectrically coupled with the conductive layer; passing electricalcurrent through the leads and into the conductive layer; and monitoringfor changes in an opposition to the current passing through theconductive layer.
 13. The method of claim 12 comprising determining aconcentration of the volatile organic compound, including providing avariation between individuals of the leads and the conductive layer;measuring the opposition to current through the conductive layer fromeach of the number of leads; and comparing the measurements to eachother.
 14. The method of claim 10 comprising providing a substrate;positioning the non-conductive layer relative to a substrate; monitoringthe substrate with the sensor device; and determining a status of thesubstrate through changes in the conductive layer.
 15. The method ofclaim 14 comprising wherein determining the status of the substratecomprises determining a degradation of the substrate by detecting thepresence of the volatile organic compound.
 16. The method of claim 10comprising measuring an opposition to current in the conductive layer;and comparing at least one of a magnitude of the opposition or a rate ofchange of the opposition to known values; and determining a type of thevolatile organic compound from the comparison.
 17. The method of claim10 comprising exposing the non-conductive layer to the volatile organiccompound; allowing the non-conductive layer to expand from the exposure;and detecting the expansion through a change in an opposition to currentin the conducting layer.
 18. The method of claim 10 comprisingmonitoring for a polar compound class as the volatile organic compound,by providing the non-conductive layer of polymethyl methacrylate. 19.The method of claim 10 comprising monitoring for a nonpolar compoundclass as the volatile organic compound, by providing the non-conductivelayer of at least one of polypropylene, or polyethylene.
 20. A methodcomprising: providing a substrate; providing a sensor device coupled tothe substrate comprising a non-conductive layer and a conductive layeroverlying the non-conductive layer constructed and arranged to measureor monitor at least one variable of a volatile organic compound; anddetermining at least one of a deformation of the non-conductive layer orsubstrate, or a change in an opposition to current in the conductivelayer to provide measurement or monitoring of the at least one variablebased on at least one calculation.